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Home › Dodge and Ram › 2000 › Ram Van B2500, Van Cargo Extended, 5.2 T › Repair and Diagnosis › Engine Performance › System › Engine Control Self-Diagnostics › Diagnostic Tests › Test NTC-3: Checking Brake Switch

Test NTC-3: Checking Brake Switch

NOTE: For connector terminal ID, see CONNECTOR IDENTIFICATION . For wiring diagram, see WIRING DIAGRAMS article.
  1. Turn ignition on with engine off. Using scan tool in INPUTS/OUTPUTS mode, read brake switch state while depressing and releasing brake pedal several times. If scan tool does not display PRESSED and RELEASED, go to next step. If scan tool displays PRESSED and RELEASED, brake switch is operating properly. Test is complete.
  2. Turn ignition off. Disconnect brake switch connector. Brake switch is located near top of brake pedal. Using ohmmeter, check resistance between ground and terminal No. 5 (Black wire) on brake switch connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open on Black wire between brake switch and ground connection. Ground connection is located directly below brake booster, on the firewall. Perform TEST VER-4 .
  3. Ensure ignition is off and brake switch connector is still disconnected. Disconnect Powertrain Control Module (PCM) connectors. PCM is located on firewall, near brake booster. Using ohmmeter, check resistance between terminal No. 6 (White/Pink wire) on brake switch connector and terminal C24 (White/Pink wire) on PCM connector C3. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open on White/Pink wire between brake switch and PCM. Perform TEST VER-4 .
  4. Ensure brake switch connector and PCM connectors are still disconnected. Disconnect 14-pin connector at CAB module. CAB module is located near battery at driver's side front corner of engine compartment. See Fig 1. On models with 4-wheel anti-lock brakes which may be referred to as Electronic Brake Control (EBC) 325, there are 2 connectors at CAB module. Connector C1 is a 14-pin connector and connector C2 is a 4-pin connector. On models with rear wheel anti-lock brakes which may be referred to as EBC 2, there is only one 14-pin connector at CAB module. Using ohmmeter, check resistance between ground and terminal C24 (White/Pink wire) on PCM connector C3. If resistance is 5 ohms or more, reinstall PCM connectors, CAB module connector and go to next step. If resistance is less than 5 ohms, repair short to ground on White/Pink wire between brake switch, CAB module and PCM. Perform TEST VER-4 .
    Fig 1: Locating Controller Anti-Lock Brake (CAB) Module
    G00014900Courtesy of DAIMLERCHRYSLER CORPORATION
  5. Using ohmmeter, check resistance between electrical terminals on brake switch that correspond with terminals No. 5 (Black wire) and No. 6 (White/Pink wire) on brake switch connector while depressing and releasing brake pedal. If resistance changes from less than 5 ohms to more than 5 ohms, replace PCM. Perform TEST VER-4 . If resistance does not change from less than 5 ohms to more than 5 ohms, replace brake switch. Perform TEST VER-4 .
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